This invention relates to an improved handle holder for mounting handles to operating poles of bush cutting machines.
Such kind of handle holder for bush cutting machines is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. HEI-6-5699 entitled xe2x80x9cMounting Structure for Operating Handle of Bush Cutting Machinexe2x80x9d or in Japanese Utility Model Laid-Open Publication No. HEI-1-32511 entitled xe2x80x9cHandle Mounting Structure.xe2x80x9d
A bush cutting machine disclosed in HEI-6-5699 has an engine provided at a proximal end of an operating pole, a drive shaft contained in the operating pole and rotated by the engine, a cutter attached to a distal end of the operating pole and rotated by the drive shaft, and a U-Shaped handle mounted via a faster to the operating pole between the cutter and the engine.
In mounting the handle to the operating pole, the operating pole is first interposed and held between upper and lower fastening parts which constitute the faster. Then the base of the U-shaped handle is inserted into a receiving hole formed in the upper fastening part in a direction orthogonal to the operating pole. Thereafter fastening bolts are inserted from bolt holes formed in the upper fastening part into screw holes formed in the lower fastening part, being screwed into the screw holes for fastening, and thereby mounting the handle to the operating pole. In short, the operating pole and the handle are fastened to one another via the fastening bolts.
During the fastening, a washer is slid into a slot which communicates with the receiving hole, extending the length of the receiving hole in the upper fastening part. The washer is formed with dislocation-preventing protrusions which are fitted into fitting portions formed in the base of the handle, thereby preventing the handle from rotating or slipping off.
In the above handle mounting structure, however, operating load of the U-shaped handle directly acts on the fastening bolts. It is therefore required that the fastening bolts be made thick or the number of fastening bolts used be increased, resulting in increased weight of the bush cutting machine. Operability of the bush cutting machine is thus lowered for long-time work with the bush cutting machine hung on a shoulder. It is further necessary to fit the protrusions formed at the washer into the fitting portions of the U-shaped handle when mounting the handle to the operating pole, and to adjust in position bolt holes formed in the washer to the bolt holes formed in the upper fastening part, taking time in assemblage.
HEI-1-32511 discloses a handle mounting structure in which a bracket is first bolt fixed to an operating pole of a bush cutting machine. A lower bracket is attached to the bracket. The base of a U-shaped handle is interposed between an upper bracket and the lower bracket and fastened via fastening bolts. A hook and a protrusion, which constitute an engagement member, are provided to the upper and lower brackets, respectively, in a position opposite to the fastening bolts, and engaged with one another. Thus, the base of the handle is fastened between the upper and lower brackets via the engagement member and the fastening bolts, so that no unbalance occurs in fastening force, enabling the handle to be firmly mounted to the operating pole.
In the above handle mounting structure, however, the bracket to which the lower bracket is attached, is attached to the operating pole via the bolt, and the fastening bolts are additionally used for mounting the handle. Thus, many bolts are used for mounting the handle to the operating pole, requiring much time for assemblage.
It is therefore an object of the present invention to provide a handle holder for bush cutting machines with reduced weight, enabling improved production efficiency.
According to an aspect of the present invention, there is provided a handle holder for fixing a handle to an operating pole of a bush cutting machine containing a drive shaft rotated by an engine driven, which comprises: a first holding member having an operating pole insertion hole for inserting the operating pole therethrough, a groove formed along the operating pole insertion hole, and a handle receiving groove orthogonal to the operating pole insertion hole, for covering substantially xc2xd of a total circumference of the handle; a second holding member having a wedge inserted into the groove, and a handle retaining groove arranged opposite to the handle receiving groove, for covering substantially xc2xd of the total circumference of the handle; and a plurality of bolts for connecting the first holding member and the second holding member; wherein, the first holding member is fixed to the operating pole with the wedge inserted into the groove, and the handle is interposed and fixed between the handle receiving groove of the first holding member and the handle retaining groove of the second holding member.
Thus in the present invention, the handle is fixed to the operating pole via the handle holder. During the fixation, the handle is interposed and held between the first holding member and the second holding member, and then the first and second holding members are fastened via the bolts. During the fastening, the operating pole and the handle holder are fixed with the wedge pressed into the groove, producing wedging effects. This leads to elimination of a bolt used only for fixing the handle holder to the operating pole, reducing the number of bolts in half, and thereby reducing the component cost and the number of assembling steps.
Further, in the present invention, the second holding member is attached to the first holding member in a direction opposite to the engine toward the cutter. With this attachment, when an operator propels the operating pole to an object to be cut such as weeds, gripping the handle, forward force also acts on the handle holder via the handle. However, the first and second holding members receive such force as to connect these members to one another via the wedge, so that only small pulling force acts on the bolts. This eliminates the need for a larger-diameter bolt for increased strength, enabling the bolts to be smaller in diameter, and thereby reducing the size of the handle holder.